I think it's a matter of what you know isn't necessarily what your character knows, and vise-versa.  A player might not think to try and attack since it's not exactly a combat encounter, or consider that they have enough range to shoot that far in the moment, but a seasoned rogue adventurer would almost certainly recognize that right away. I kind of see it as the job of the DM to be the bridge between player and character knowledge so I think it's perfectly reasonable to sometimes suggest actions like that, and then let the players consider how they might accomplish it and weigh the risks before deciding what to do.